Image-guided surgery technology has been clinically available since the mid-1980s. Analogous to global positioning systems (GPS), image-guided surgery facilitates intraoperative surgical navigation by linking preoperative radiographs to intraoperative anatomy. Central to the image-guided surgery process is registration: the linking of the radiographic images to the patient. To achieve high accuracy, the registration is based on fiducial markers that are identified both in the radiographs and on the patient. Fiducial markers need to be positioned by anchors, which have been used in other medical procedures as well.
A current system for image-guided surgery requires that self-tapping anchors be screwed into a patient's skull through an incision in the scalp. The fact that the anchor cannot be seen by a medical professional such as a surgeon during the screwing because of overlying scalp makes it difficult for the surgeon to know when and whether the anchor is fully seated against the skull. The anchor is placed into a driver that is inserted through the incision. The surgeon presses on the driver and begins to twist. If the surgeon twists too far, the threads that are tapped into the skull by the anchor will be stripped. If the surgeon does not twist far enough, the threads on the anchor will not be fully buried in the skull. In either case, the anchor will not be secure.
Therefore, a heretofore unaddressed need still exists in the art to address the aforementioned deficiencies and inadequacies.